/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.consensus.ratis;

import org.apache.iotdb.common.rpc.thrift.TSStatus;
import org.apache.ratis.protocol.Message;
import org.apache.ratis.thirdparty.com.google.protobuf.ByteString;
import org.apache.thrift.TException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ResponseMessage implements Message {

    /**
     * This content holder may hold 1. TSStatus, which may be serialized when called getContent() 2.
     * DataSet, which never need to be serialized
     */
    private final Object contentHolder;

    private volatile ByteString serializedData;
    private final Logger logger = LoggerFactory.getLogger(ResponseMessage.class);

    public ResponseMessage(Object content) {
        this.contentHolder = content;
        this.serializedData = null;
    }

    public Object getContentHolder() {
        return contentHolder;
    }

    @Override
    public ByteString getContent() {
        if (serializedData == null) {
            synchronized (this) {
                if (serializedData == null) {
                    assert contentHolder instanceof TSStatus;
                    TSStatus status = (TSStatus) contentHolder;
                    try {
                        serializedData = ByteString.copyFrom(Utils.serializeTSStatus(status));
                    } catch (TException e) {
                        logger.warn("serialize TSStatus failed {}", status);
                    }
                }
            }
        }
        return serializedData;
    }
}
